Forget Klondike bars—what would you do for an Amazon gift card? According to a new study, for many people, the promise of free credits to a favorite retailer is enough to help them stick to a medication regimen.

Forget Klondike bars—what would you do for an Amazon gift card? According to a new study, for many people, the promise of free credits to a favorite retailer is enough to help them stick to a medication regimen.